Just starting with the basics, have you checked the aspect ratio on your tv? You should be able to switch the aspect ratio using a button on the remote. If you're running your NUC at 1080p the aspect should be set to "dot-to-dot" or something similar. Here are the instructions for your model:

Jason - I recommend avoiding overscan in TV settings when possible, but if TV must overscan then what you are looking for in the Intel driver is Display Settings - Scaling - Customize Aspect Ratio, then you slide the horizontal and vertical sliders to something less than 100, and Apply.